I did English and Lit a years ago (not englang) but from what I know, Lit requires a different sort of analysis. Both are heavily based on the language in a text or situation, but Englang has a more definitive marking scheme and slightly more clear cut right and wrong answers. Literature is all about interpretations, so whilst the analytical skills might be transferrable, the way you write will be very different.
The adage I've heard from a lot of teachers is that if you like English, you'll like Lit or EngLang more. It might not be a common combination, but if you find English enjoyable and like the sounds of both subjects, then there's no reason why doing both shouldn't be an option.
In my experience, it's worth sussing out which teachers take which subjects (if you can find out.) Having someone you don't get along with or who doesn't teach well for Lit is awful because it's near impossible to learn on your own, I'd imagine it's similar in Englang. It's not the end of the world if this does end up happening, but it might help to consider while subject selection is still open
